Biology confusion! 10 points to best answer!?

[Rose L]

1. Which of the following is correct about a muscle contraction?
Sarcomeres produce actin and myosin.
Myofibrils attach to Z lines.
Myosin heads attach to sites on actin filaments.
ATP causes fascicles to contract muscle fibers.


2. Which structure is composed of the filaments actin and myosin?
sarcomere
myofibril
muscle fiber
fascicle


3. Which statement is correct about how muscles move bones?
Extensors cause a bone to move initially.
Tendons connect extensors and flexors to each other.
The insertion is where a muscle attaches to the bone it wants to move.
The origin is where only flexors attach to move a nearby bone.